The invention relates generally to the field of dunnage devices, or void fillers, designed for use within shipping containers or transport vehicles. Such devices are used in conjunction with the packages, boxes, or pallet loads being shipped, so that the loaded goods and the dunnage devices substantially fill the volume of the transport vehicle. In this manner, potentially damaging shifting or toppling of the load into adjacent voids is avoided during transit.
More particularly, the invention pertains to dunnage devices constructed preferably from strips of corrugated paperboard. The strips are configured and assembled to be expandable from a compact flat stack into a vertically extending, cellular slab, adapted to resist compressive forces applied against the major faces of the slab. A hanging device, either resting over the load or attached to an adjacent wall, is typically used to suspend and maintain the slab in an expanded condition.
Representative of such a prior art dunnage device is the cellular void filler shown in U.S. Pat. No. 4,372,717, issued to Sewell et al. The device illustrated in the '717 Patent forms a "honeycomb" slab, including a plurality of generally square and diamond shaped cells, when expanded. Such a void filler is particularly useful when employed with a pallet load having individual boxes or cases, as the slab face of the filler has relatively small cells, presenting many support and contact edges for the plurality of boxes. Honeycomb void fillers are also relatively strong, owing to the fairly high percentage of exposed corrugated material within the face of the slab. Thus, honeycomb void fillers are suitably adapted for applications where large fore and aft stresses are encountered during transit, and imposed upon the slab.
However, other applications exist where the pallet load is formed by a plurality of individual containers, or packages, about which a resilient film has been stretch or shrunk-wrapped. In this instance, the film-wrapped pallet, composed of individual packages, is transformed into a unitary load which does not require abutting support and restraint of each container during transit. In other words, the stretch-wrap material acts to hold the individual containers together as a unit, so the void filler is only called upon to support and restrain the entire unit. This allows the use of a void filler having much larger cells, and requiring less corrugated paperboard material to fabricate.
There are also applications where the stresses or forces imposed upon the void fillers are relatively light, either as a consequence of the nature of the load, or because only lateral, swaying forces are to be restrained. It is for these applications, where the need exists for a less expensive, and lighter duty void filler.